71 340 Compression Test

nm9stheham said

205 with a 280 cam? I would have that gauge checked.

The stock compression ratings were quite a bit higher than reality. We have a fresh 340 with a real 10:1 SCR and a 268 advertised cam duration with 4-5 degrees cam advance and the compression is around 160 psi.

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I ran the comp test with multiple gages and they were within 3psi of each other.
Besides the 280H .480/.480 lift cam I had also swapped out the original heads with a friend for his small chambered 67 Camaro 302 Cid heads. He wanted to install a small B&M blower on the 302 and wanted to lower his base compression. This was a SB Chevy that I was referring to with the 205 psi.
Engine is out of the little cuda now, getting her ready for paint shop. Going to pull a valve cover this evening to get head casting numbers and determine if possible what the intake valve sizes are.